Holemaking such as drilling has long been known in the metalcutting art. Holemaking using drills or mills with cutting inserts thereon has also long been known in the art. On example of such a drill with a carbide cutting insert is shown in U.S. Pat. No. 4,659,264 issued to Kennametal Inc. The drill has a shank with at least one cutting insert on one end of the shank.
Drills and milling cutters have developed from this early technology into more complex drill bodies and milling heads with multiple inserts thereon positioned at particular angles, locations and overlaps to provide more rapid drilling and milling and/or better finished surfaces. On such milling head is shown in U.S. Pat. No. 5,672,031 issued to Kennametal Inc. Numerous such drill bodies are shown on pages 75-134 in Kennametal's Drilling Catalog #7061 which was printed and copyrighted in 1996.
In either case, cutting inserts are being used to provide replaceable cutting faces as well as more unique drill and/or mill designs that are capable of more than merely simple holemaking.
One such example is the milling cutters that have been designed to perform multiple functions at one time such as plunge and face milling. One such milling cutter is shown in U.S. Pat. No. 5,542,795 issued to Kennametal Inc.
Other examples are the edge chamfering or deburring drills shown in U.S. Pat. Nos. 5,173,013 and 5,288,184. The '013 patent shows a hole cutting and chamfering tool having a hole cutting insert 4 followed by chamfering inserts 10 and 14, all of which are aligned in a longitudinal manner along the tool. The '013 tool is operative to cut a hole through a workpiece and then chamfer the edges surrounding the hole on opposite sides of the workpiece using the tool from one side without having to remove the tool from the hole.
The '184 patent shows a deburring tool for deburring bore edges of bores. This tool does not hole make and rather deburs a made hole using knives 9 and 12 on opposite entrance and exit edges of the hole. In addition, cutting tool 13 is a plane knife which provides a plane surface in the hole.
These numerous drilling and milling tools are satisfactory for the intended or described objectives. However, it is a desired of those in the holemaking industry to have one tool that makes or cuts the hole in the workpiece and chamfers the entrance and exit edges in a controlled, balanced circle-interpolating manner. It is further desired of those in the holemaking industry to have one tool that makes or cuts the hole in the workpiece, chamfers the entrance and exit edges in a controlled and balanced circle-interpolating manner, and forms a groove, slot or threads within the workpiece between the entrance and exit edges and/or in the entrance face around the hole.